1 Local dev
SQLite needs nothing. Drop a file, start the service, done. Use it for local work and for tiny teams.
2 Production SQL
Postgres first. MySQL and SQL Server if your org already runs them. The suite uses sqlx-style drivers and Atlas migrations, so the schema is identical across engines.
3 When to pick NoSQL
Mongo and Elasticsearch make sense where services record message streams — Buzz and Switchboard use them for async recording. Elasticsearch unlocks full-text search.
4 Migrations
Atlas runs on every boot. Schema drift is caught at startup; the service refuses to run if the DB isn’t at the expected version.